[Nepomuk] Re: Akonadi <-> Nepomuk interaction

[Christian Mollekopf]

Just one thing which I forgot.

The point is that I need to annotate the content (text) of the Todo/Note not 
the Todo/Note itself.

I annotate the content with pimo:Topics and random items like files, other 
akonadi items, etc. 
If I would simple set the Thing which I annotated with those items as the 
Thing of the Todo/Note directly, another application could add annotation to 
the Thing i.e. a location for a Todo. 
Now that annotation is really only valid for the Todo not the content in 
general. So if that item is converted to a Note, the location annotation 
should not be kept, while all the associated files, etc and pimo:Topics are 
still valid as they are actually annotations of the content (text).

That was also why I used the separate resource (for annotating the content of 
the todo/note).

Cheers,

Chris

On Tuesday 22 February 2011 14:31:10 Sebastian Trüg wrote:
> Hi Chris,
> 
> On 02/22/2011 02:23 PM, Christian Mollekopf wrote:
> > On Tuesday 22 February 2011 11:41:27 Sebastian Trüg wrote:
> >> Hi Chris,
> >> 
> >> I always figured that there would be only two resources:
> >> 1. The main indexed resource created by the feeder
> >> 2. The pimo:Thing that contains all the annotations and relations.
> >> 
> >> IMHO there is no need for a third resource which is maintained by your
> >> app. The only problem I see here is the update by the feeder since that
> >> should maintain the relation to the pimo:Thing.
> >> But I think that could be handled by the feeder. It simply needs to
> >> handle updates differently than a simple delete+add. Instead it should
> >> make sure the resource URI is reused and the relation to the pimo:Thing
> >> is kept.
> > 
> > The problem with using the Resource created by the feeder is that it is
> > not clear if my app or the feeder is first to create it, so I would have
> > to make sure that also if I create the Resource first, the feeder reuses
> > it. But I guess that should be possible.
> 
> AFAIK Akonadi uses a dedicated property to identify their resources. You
> could reuse that.
> I suppose it would be best to put that into shared code somehow. That
> way it can be assured that the resources are reused.
> 
> > Further I also have to see when to delete the Thing, as sometimes I wan't
> > to reuse it (when converting the item).
> > 
> > What I don't really get: for one specific note there should only be one
> > Thing, right? So If I create the Thing and assign it to the Resource
> > created by the Feeder, will the feeeder delete the Thing, when he
> > deletes the Resource or will I have to do that?
> > 
> > The ownership of Resources/Things is not yet really clear to me....
> 
> The feeder does not delete the things. This is something that is not
> defined yet. It could of course be very easy to add thing deletion to
> the feeder.

In this case
> 
> Cheers,
> Sebastian
> 
> >> Once that works you might only have to update the pimo:Thing type. I am
> >> not sure if this should also be done in the feeder or if your app should
> >> do that.
> >> 
> >> Cheers,
> >> Sebastian
> >> 
> >> On 02/19/2011 02:33 PM, Christian Mollekopf wrote:
> >>> Hi,
> >>> 
> >>> As I don't feel that there is a real solution how to handle notes and
> >>> kcal items in akonadi and nepomuk.  I'm going to explain here how I
> >>> plan to implement the interaction between aknoadi::items and
> >>> nepomuk::resources in my application.
> >>> 
> >>> I know there is some work going on in Baske/Semnotes/Kjots and the
> >>> issue has been discussed before focusing on notes. But as I couldn't
> >>> find a real conclusion on the ml, and since I have some more
> >>> requirements/usecases, I think it is time to continue this discussion
> >>> =)
> >>> 
> >>> Usecase:
> >>> My application manages Incidences (todos/events) and Notes using the
> >>> KCal and Akonotes resource in akonadi. (I do believe that storing
> >>> those in akonadi is the right way, and storing them in nepomuk is not
> >>> a valid option for various reasons).
> >>> 
> >>> I organize all items using PIMO::Topics (instead of collections inside
> >>> akonadi). Further I plan to add functionality to associate random data
> >>> (files, websites, mails, ...) with the topics and/or a certain
> >>> Akonadi::Item using Nepomuk.
> >>> 
> >>> One functionality which showed some further requirements, is converting
> >>> i.e. a note to an incidence. This made me realize that I'm normally
> >>> actually tagging the Content of the note/event/todo and not i.e. todo
> >>> itself.
> >>> 
> >>> 
> >>> All of this lead me to the following conclusion how to handle those
> >>> items in Nepomuk:
> >>> 
> >>> For each Akonadi::Item I create a Nepomuk::Resource (Content Resource)
> >>> of the type NFO:HtmlDocument (since it is only the content, not the
> >>> task itself) with an identifier consisting of an application-specific
> >>> prefix + akonadi::item url (to avoid conflicts with the items
> >>> generated in the nepomukfeeder agents). For all annotations I use the
> >>> pimoThing (Content Thing), on which I set the type PIMO:Document. (See
> >>> the attached diagram for reference)
> >>> 
> >>> So if I convert the item i.e. from note to todo, which means deleting
> >>> the old Akonadi::Item and creating a new one, I simply set the new
> >>> Nepomuk::Resource (created with the new akonadi::item url) as a
> >>> groundingOccurence of the existing Pimo:Document. This way all
> >>> annotations remain untouched.
> >>> 
> >>> The obvious downside of this is, that other applications do not profit
> >>> from annotations made in my application, and I am not yet sure how to
> >>> overcome this. Maybe I can annotate the Nepomuk::Resource which has
> >>> been created by the feederagent with the Pimo:Document of the same
> >>> item, and therefore implicitly share the annotations?
> >>> 
> >>> Also I am not storing any real content in those Resources, I use the
> >>> Content Resource and the Content Thing only to annotate the content of
> >>> the item. For fulltext search or similar things I expect to use the
> >>> items created by the FeederAgent (meaning I will have to create a
> >>> feederagent for notes as well).
> >>> 
> >>> 
> >>> Anyhow, this solution doesn't seem ideal, so I'd be interested how you
> >>> guys intend to solve the issues. Especially what Resources you create
> >>> and how you tell them apart from the ones created by the Feederagents.
> >>> 
> >>> Also are you using Nepomuk purely internal, or do you actually create
> >>> content which could be reused by other applications?
> >>> 
> >>> Cheers,
> >>> 
> >>> Chris
> >>> 
> >>> PS: Some background info on my app in case youre interested
> >>> http://gitorious.org/notetaker/pages/Home
> >>> 
> >>>